1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Gen 3 Gas Engine Running Rough

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by testriderchuck, Apr 12, 2020.

  1. testriderchuck

    testriderchuck New Member

    Joined:
    Feb 9, 2020
    10
    3
    0
    Location:
    E washington
    Vehicle:
    2010 Prius
    Model:
    N/A

    My '10 (bought Oct '19 with 135K, now 190K) started doing that a couple months ago. Using it for long distance delivery, 400+ miles a day. Initially it was only on gentle accel, has progressed to shuddering at any steady speed between about 25 and 75mph. shudder stops when ICE stops. Dealer told me the evap was full of liquid because I "topped it off" (that's a design problem) . I took the canister out a couple days ago, not only was there no liquid fuel in it, there was BARELY A SMELL of fuel.

    Disconnected and plugged the purge from the canister. no help
    Unplugged the wire to the vacuum solenoid (purge valve) by the intake. no help
    Unplugged the purge hose from the valve and plugged it to prevent air leaks. haven't driven it yet as of this post but not holding my breath
    Saw something about bad spark plugs, realized hafta remove everything in front of the windshield to change them. Not tried yet.

    My first thought was that there was a clutch involved somewhere, that's why I got the warranty (which the Toy dealer cut the miles in half because "I was gonna put miles on real fast"). never buy from that dealer again...

    Kinda afraid to "reboot" vehicle due to the cursed backup beep that might revert to factory default, dealer wants $75 to turn each one off. but that's another story...

    ideas?
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,781
    48,987
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    maybe the egr, or headgasket. are you losing any coolant?
     
    Mendel Leisk likes this.
  3. testriderchuck

    testriderchuck New Member

    Joined:
    Feb 9, 2020
    10
    3
    0
    Location:
    E washington
    Vehicle:
    2010 Prius
    Model:
    N/A
    If coolant is going away it's not very fast. Currently AT the min line, maybe a bit above.

    I see other's having issues apparently related to the EGR failing and causing other issues, eventually blowing the H/G. what happens (other than allegedly horrible emissions and CEL on) if the wires to the EGR are disconnected?
     
    #3 testriderchuck, Apr 12, 2020
    Last edited: Apr 12, 2020
  4. PriusUkTech

    PriusUkTech Junior Member

    Joined:
    Mar 28, 2020
    7
    2
    0
    Location:
    UK
    Vehicle:
    2010 Prius
    Model:
    ----UK----
    Clean the EGR it comes a part, and EGR cooler your cooler will be blocked use cellulose Thinner's in a bucket for the cooler leave it in the bucket overnight then clean out until you can see day light through both ends

    next take off your air inlet manifold clean it and behind it you will find your PCV valve fit a new one or you can clean the old one in the bucket it should rattle freely when shaken

    once done it will fix your problems
     
  5. testriderchuck

    testriderchuck New Member

    Joined:
    Feb 9, 2020
    10
    3
    0
    Location:
    E washington
    Vehicle:
    2010 Prius
    Model:
    N/A
    Would temporarily disconnecting the EGR valve wire (disabling the EGR) be a valid troubleshooting step?
     
    PriusUkTech likes this.
  6. HaYon Prius driver

    HaYon Prius driver New Member

    Joined:
    Dec 10, 2019
    9
    4
    0
    Location:
    Tracy, Ca
    Vehicle:
    2013 Prius
    Model:
    Two
    I'll bet you have oil in your intake and your EGR system is clogged. I had this same issue on my 2013 toyota prius 2 at around 180k miles. It started as rough starts then the check eng light came on with the #1 cylinder misfire code. I changed the coil pack and all spark plugs they were do for replacement anyways. Check eng light went away and things seemed fine for a day. Rough start came back so I cleaned the EGR and intake Systems, replaced all those seals and the PCV valve. Things were good for about a week and then it came back. Looked in my intake and there was a small puddle of oil again. I Was thinking of getting an oil catch can but I didn't yet. I decided to borrow a borescope and check out the cylinders and pistons through the spark plug holes. I did this when the eng was cold and just seen gunk and put it back together. I decided to look at it again the next day but this time I ran the car before I pulled the plugs. When I scoped it this time I seen what looked like water drops down the #2 cylinder. At first I thought maybe fuel injector was leaking into intake but then I realized it was on the back wall near the exhaust valves. I watched as the drip would form and then run down the cylinder. It took about a minute for the drip to form. Then I knew I needed to atleast replace the head gasket. I read on another thread that someone had the same leak in cylinder #2 . I never notice any oil or coolant loss between oil changes so it must have just started leaking. I have now completely torn apart the engine. I have decided to change the pistons and rings IAW the TB for excesssive oil consumption hoping that fixes the oil getting into my intake through the PCV valve. Good luck! I would start by pulling of your airfilter cover and tube that goes to the intake and look in through the intake valve. See if there is a puddle of oil. If so you should take it off and clean it all out and the EGR system. Then maybe look into an oil catch can.